Calculateur de Plots de Terrasse — Formule
## How to Calculate Deck Footings
### Formula
**Beam Rows = floor(Deck Width / Beam Spacing) + 1**
**Footings per Row = floor(Deck Length / Footing Spacing) + 1**
**Total Footings = Beam Rows × Footings per Row**
**Concrete per Footing = pi × r² × depth / 27**
Footing spacing is typically 6-8 ft for 2×8 beams or 8-10 ft for doubled 2×10 or 2×12 beams. Footing depth must extend below the frost line per local building code.
### Formula
**Beam Rows = floor(Deck Width / Beam Spacing) + 1**
**Footings per Row = floor(Deck Length / Footing Spacing) + 1**
**Total Footings = Beam Rows × Footings per Row**
**Concrete per Footing = pi × r² × depth / 27**
Footing spacing is typically 6-8 ft for 2×8 beams or 8-10 ft for doubled 2×10 or 2×12 beams. Footing depth must extend below the frost line per local building code.
Exemple Résolu
A 16×12 ft deck with 8 ft footing spacing, 6 ft beam spacing, 12-inch diameter footings 42 inches deep.
- Beam rows = floor(12 / 6) + 1 = 3 rows
- Footings per row = floor(16 / 8) + 1 = 3 footings
- Total footings = 3 × 3 = 9 footings
- Footing radius = 12 / 2 / 12 = 0.5 ft
- Concrete per footing = 3.14159 × 0.5² × 3.5 / 27 = 0.102 cu yd
- Total concrete = 9 × 0.102 = 0.92 cu yd